A Novel Endoscopic Polypectomy Surveillance Protocol Is Highly Reliable For Detecting Dysplastic Fundic Gland Polyps In Familial Adenomatous Polyposis Syndrome

Fundic gland polyps (FGPs) are typically seen in abundance in patients with familial adenomatous polyposis (FAP). These FGPs are generally considered innocuous and biopsy sampling is not routinely done. Conventional forceps biopsy may be time-consuming or have sampling error. Since 2001, we have used a novel endoscopic polypectomy surveillance (EPS) technique to evaluate FGPs for dysplasia and/or cancer. To evaluate the clinical value and safety of EPS technique in detecting FGP dysplasia and to identify endoscopic features for dysplasia in FAP patients. This is a retrospective study of FAP patients with FGPs who underwent EPS. Adult patients referred for surveillance of duodenal adenomas between August 2001 to August 2019 were enrolled. Whole FGPs were removed with our EPS method, which involved cold-snaring a minimum of 20 FGPs from different regions of the proximal stomach (Image 1A). Resected polyps were collected by suctioning after water irrigation. Demographic, clinical, endoscopic, and histopathologic features were reviewed. Statistical methods included Wilcoxon rank-sum test for continuous variables and Fisher’s exact test for categorical variables. The mean duration of endoscopic follow-up was 5.9 years (± 3.4) and the mean interval between surveillance endoscopies was 12.9 months (± 8.1). 118 EPS sessions were carried out on 35 patients who had FGPs. Dysplasia was found in 87 of these procedures (73.7%). EPSs were successfully performed in 100% of cases and were completed within 10 minutes. Average number of polyps or large polyp fragments obtained per EPS procedure was 33.5 (± 40.1). 93.2% of follow-up EPSs in patients showed the same biopsy results from prior procedures or histological progression. 57.1% of patients had developed dysplasia by their most recent EPS; an additional 15% had foci of signet ring cells within their FGPs (n=2) or metastatic gastric cancer. Significant risk factors for dysplasia and/or cancer were polyps >10mm in size (p<0.001) and carpeting of polyps (p=0.002) (Table 1). There were no significant EPS-related complications of bleeding or perforation and no readmissions within 30 days. Dysplasia or higher-grade pathology is common in FGPs among adult patients with FAP. EPS is a safe and effective method for endoscopic surveillance with reproducible and progressive results over time. Endoscopic features of large polyp size >10mm and carpeting of polyps are associated with dysplasia and/or cancer.Image 1A. Images A, B, and C demonstrate a novel tissue sampling technique, endoscopic polypectomy surveillance, in patients with FAP who have FGPs.View Large Image Figure ViewerDownload Hi-res image Download (PPT)